Stuffing method and apparatus

Abstract

Method and apparatus for stuffing food product into shirred casing in which a stuffing machine designed to stuff fully soaked casing is adapted to the use of controllably premoisturized casing. An internal sizing ring stretches the casing to about its recommended stuffed circumference so that the stuffing pressures required to fill the casing are reduced to manageable proportions. During the clipping cycle an increase in product pressure is avoided, by creating slack during the constricting phase of the gathering and clipping operation, and by gripping more tightly with the second tie gripper than with the first.

We claim as our invention: 
     
       1. A method of stuffing a flowable product into casing lengths deshirred from a shirred casing supply having a closed first tie end comprising the steps of: a. stuffing a desired amount of the product into the casing supply while applying a holdback force to the casing to achieve a desired stuffed pressure;   b. constricting the encased product with closely spaced first tie and second tie gates to close the second tie end of the encased product;   c. prior to completion of the constricting step creating slack in the casing supply so that the stuffed product displaced during constricting is forced into the slack casing and the encased product pressure is not substantially increased;   d. separating the first tie and second tie constricting gates while gripping the casing more tightly with the second tie gate than with the first tie gate so that the product displaced during separating is displaced into the slack casing and the encased product pressure is not substantially increased; and   e. applying second tie and first tie clips, severing the casing therebetween and releasing the gates.   
     
     
       2. In a method of stuffing a flowable product into casing lengths deshirred from a shirred casing supply, the improvement comprising the steps of: a. stuffing a desired amount of the product into a length of the casing while applying a holdback force to the casing to achieve a desired stuffed pressure;   b. constricting the encased product with closely spaced first tie and second tie gates until said gates grip the casing to close the second tie end;   c. prior to completion of the constricting step creating slack in the casing supply so that the stuffed product displaced in constricting is forced into the slack casing;   d. separating the first tie and second tie constricting gates while gripping the constricted casing more tightly in the second tie gate so that slippage between the casing and gates occurs at the first tie gate, whereby the desired stuffed pressure is substantially unchanged during the constricting and separating steps.   
     
     
       3. The method as set out in either of claims 1 or 2 wherein the step of creating slack is performed prior to the initiation of the constricting step. 
     
     
       4. The method as set out in either of claims 1 or 2 wherein the casing supply is controllably premoisturized prior to shirring and wherein the retarding force is applied by stretching the casing to about its desired stuffed circumference. 
     
     
       5. The method as set out in claim 4 in which the shirred casing supply is compressed in place on a plastic sleeve, and the step of creating slack comprises reciprocating said sleeve to release the slack casing. 
     
     
       6. The method as set out in claim 5 wherein the step of reciprocating includes controlling the length of the reciprocating stroke to thereby control the length of slack casing which is created. 
     
     
       7. In a method of stuffing flowable product, using a stuffing machine of the type compatible with a range of stuffing pressures associated with fully soaked casing, and of the type having a double clipper which constricts the stuffed product by means of a pair of gates, separates the gates, then applies a pair of clips, an improvement in said method for achieving stuffing pressures within said range with less pliable controllably premoisturized casing, said method comprising the steps of creating a holdback force during stuffing by stretching the casing to about its recommended stuffed circumference so as to stuff the casing to its recommended circumference while limiting stuffing pressures within said range, slacking the casing prior to completing the constricting phase of clipper operation so that substantially all of the product displaced during constricting is displaced into the slack casing so as not to increase pressure within the stuffed product, and gripping the second tie gates tighter than the first tie gates during the separating operation so as to prevent a pressure increase in the product during separation. 
     
     
       8. The method as set out in claim 7 wherein the step of slacking is performed prior to initiation of the constricting phase of clipper operation. 
     
     
       9. An improvement in a stuffing machine of the type compatible with a range of stuffing pressures associated with fully soaked casing, and of the type having a double clipper which constricts the stuffed product by means of a pair of gates, separates the gates, then applies a pair of clips, the improvement in said machine for achieving stuffing pressures within said range with less pliable controllably premoisturized casing, comprising in combination, sizing means for creating a holdback force during stuffing by stretching the casing to about its recommended stuffed circumference so as to stuff the casing to its recommended circumference while limiting stuffing pressures within said range, means for slacking the casing prior to completing the constricting phase of clipper operation so that substantially all of the product displaced during constricting is displaced into the slack casing so as not to increase pressure within the stuffed product, and means for gripping the second tie gates tighter than the first tie gates during the separating operation so as to prevent a pressure increase in the product during separation. 
     
     
       10. The improvement as set out in claim 9 wherein the means for slacking comprises a tension sleeve for carrying the casing supply and the sizing means, said tension sleeve being mounted in an operative position on the stuffing machine, and means for reciprocating the tension sleeve to create the slack casing. 
     
     
       11. The improvement as set out in claim 10 in which the means for reciprocating includes a linear to rotary to linear actuator. 
     
     
       12. The improvement as set out in either of claims 10 or 11 in which the reciprocating means includes adjustment means to set the length of the reciprocating stroke, thereby to control the length of the slack casing which is created. 
     
     
       13. The improvement as set out in either of claims 9 or 10 wherein the means for gripping comprises means for increasing the gripping force of the second tie gripper to a level higher than that of the first tie gripper. 
     
     
       14. In a clipper for a stuffing machine having a pair of gathering gates through which a stuffed product passes, each gate including an opposed pair of generally V-shaped gathering jaws which are brought together to progressively constrict the product until the junctions of the V's are juxtaposed to grip the casing and close the product, the pair of gates thereupon being adapted to separate laterally while gripping the casing to form a casing tail, the improvement comprising, a gate insert for increasing the gripping force of one gate on the casing to a higher level than that of the other gate, the insert including a pair of closely spaced end members each having a generally V-shaped edge to conform with the shape of the jaws, but having a junction at the V which is less deep than that of the jaws; means joining the end members along the V-shaped edge to form a channel between the end members open opposite the V-shaped edge, the channel being dimensioned to snugly fit one of the jaws of the gathering gate when said channel is slid thereover, and locating means to position the insert on the gate with the V-shaped edge generally conforming to the edge of the jaw, whereby the reduced depth of the V of the insert causes the gate to grip more tightly. 
     
     
       15. The improvement as set out in claim 14 wherein one of the end members has sufficient resilience to allow slight deflection thereof as said insert is slid over said jaw, thereby increasing the holding force of the insert on the jaw. 
     
     
       16. A slacker for a stuffing machine comprising in combination, a tension sleeve for carrying a casing supply and adapted to be mounted for reciprocation on the stuffing machine, attachment means for engaging the tension sleeve and for reciprocating same between two positions, a sliding block constrained for reciprocation along an axis parallel to the tension sleeve, means attaching the sliding block to the attachment means, the sliding block including a slot disposed perpendicularly to its axis of reciprocation, a rotatable member having an axis of rotation, a drive cam carried by the rotatable member, the drive cam being disposed within the slot in the sliding block, the rotatable member including means for offsetting the axis of the drive cam from the axis of rotation, and means for rapidly rotating the rotatable member about its axis and through a predetermined angle thereby to cause the drive cam to act through the sliding block and cause a reciprocation of the tension sleeve from a first to a second and back to the first position. 
     
     
       17. The slacker as set out in claim 16, wherein the rotatable member includes a lead screw and a block engaged therewith for translating one of said axes with respect to the other, thereby to adjust the length of the reciprocating stroke of the tension sleeve. 
     
     
       18. The slacker as set out in claim 16 wherein the rotatable member includes a drive pinion, a pneumatic cylinder, and a rack on the operating rod of the cylinder engaging the pinion, whereby a unidirectional stroke of the cylinder causes rotation of the rotatable member through said predetermined angle. 
     
     
       19. In a casing closure clipper for stuffing apparatus which includes first and second casing gathering gates through both of which product stuffed casing passes, each of said first and second casing gathering gates including a pair of juxtaposed casing gathering jaws controllably moveable between an open position wherein the product stuffed casing is unconstricted, and a closed position wherein the product stuffed casing is constricted, and includes means to controllably longitudinally separate said gates when the jaws are in said closed position to form a substantially product-free casing tail to accommodate a casing closure step, the improvement comprising, in combination: first means as a feature on one pair of said jaws and   second means as a feature on the other pair of said jaws,   said first means constructed to define a substantially complete closure constriction of said casing when its pair of jaws is in said closed position, and   said second means constructed to define a less than complete closure constriction of said casing when its pair of jaws is in said closed position.   
     
     
       20. Apparatus according to claim 19 wherein at least one of said first means and said second means comprises a modified casing contacting surface on one of said jaws of said pair of said jaws. 
     
     
       21. Apparatus according to claim 20 wherein said contacting surface on said one pair of said jaws is modified to define a V-shaped aperture with an apex of lesser depth than corresponding V-shaped apertures in the others of said jaws. 
     
     
       22. Apparatus according to claim 20 wherein the modified casing contacting surface on one of said jaws of said pairs of jaws comprises an adapter element attached to said jaw. 
     
     
       23. Apparatus according to claim 22 wherein said adapter element defines a V-shaped aperture with an apex of lesser depth than corresponding V-shaped apertures on the others of said jaws.